WO2017184458A1 - Alimentation électrique à variation de signal unique pour une pluralité d'amplificateurs - Google Patents

Alimentation électrique à variation de signal unique pour une pluralité d'amplificateurs Download PDF

Info

Publication number
WO2017184458A1
WO2017184458A1 PCT/US2017/027743 US2017027743W WO2017184458A1 WO 2017184458 A1 WO2017184458 A1 WO 2017184458A1 US 2017027743 W US2017027743 W US 2017027743W WO 2017184458 A1 WO2017184458 A1 WO 2017184458A1
Authority
WO
WIPO (PCT)
Prior art keywords
power supply
amplifiers
signal
amplifier
control circuit
Prior art date
Application number
PCT/US2017/027743
Other languages
English (en)
Inventor
Jeffrey LABUNDY
Anu Chakravarty
Deepal SHRISHRIMAL
Jeffrey Allen May
Firas Azrai
Original Assignee
Cirrus Logic International Semiconductor, Ltd.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Cirrus Logic International Semiconductor, Ltd. filed Critical Cirrus Logic International Semiconductor, Ltd.
Publication of WO2017184458A1 publication Critical patent/WO2017184458A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
    • H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
    • H03F1/0211—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers with control of the supply voltage or current
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F1/00—Details of amplifiers with only discharge tubes, only semiconductor devices or only unspecified devices as amplifying elements
    • H03F1/02—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation
    • H03F1/0205—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers
    • H03F1/0211—Modifications of amplifiers to raise the efficiency, e.g. gliding Class A stages, use of an auxiliary oscillation in transistor amplifiers with control of the supply voltage or current
    • H03F1/0216—Continuous control
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/181—Low-frequency amplifiers, e.g. audio preamplifiers
    • H03F3/183—Low-frequency amplifiers, e.g. audio preamplifiers with semiconductor devices only
    • H03F3/187—Low-frequency amplifiers, e.g. audio preamplifiers with semiconductor devices only in integrated circuits
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
    • H03F3/21—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only
    • H03F3/211—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only using a combination of several amplifiers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
    • H03F3/21—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only
    • H03F3/213—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only in integrated circuits
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/20—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers
    • H03F3/21—Power amplifiers, e.g. Class B amplifiers, Class C amplifiers with semiconductor devices only
    • H03F3/217—Class D power amplifiers; Switching amplifiers
    • H03F3/2175—Class D power amplifiers; Switching amplifiers using analogue-digital or digital-analogue conversion
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F3/00—Amplifiers with only discharge tubes or only semiconductor devices as amplifying elements
    • H03F3/68—Combinations of amplifiers, e.g. multi-channel amplifiers for stereophonics
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R3/00—Circuits for transducers, loudspeakers or microphones
    • H04R3/12—Circuits for transducers, loudspeakers or microphones for distributing signals to two or more loudspeakers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/03—Indexing scheme relating to amplifiers the amplifier being designed for audio applications
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/228—A measuring circuit being coupled to the input of an amplifier
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/321—Use of a microprocessor in an amplifier circuit or its control circuit
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/462—Indexing scheme relating to amplifiers the current being sensed
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/471—Indexing scheme relating to amplifiers the voltage being sensed
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/504—Indexing scheme relating to amplifiers the supply voltage or current being continuously controlled by a controlling signal, e.g. the controlling signal of a transistor implemented as variable resistor in a supply path for, an IC-block showed amplifier
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03F—AMPLIFIERS
    • H03F2200/00—Indexing scheme relating to amplifiers
    • H03F2200/511—Many discrete supply voltages or currents or voltage levels can be chosen by a control signal in an IC-block amplifier circuit

Definitions

  • the present disclosure relates in general to circuits for audio devices, including without limitation personal audio devices such as wireless telephones and media players, and more specifically, to a single signal-variant power supply for supplying a supply voltage to a plurality of amplifiers or other load.
  • Personal audio devices including wireless telephones, such as mobile/cellular telephones, cordless telephones, mp3 players, and other consumer audio devices, are in widespread use.
  • Such personal audio devices may include circuitry for driving a pair of headphones or one or more speakers.
  • Such circuitry often includes a power amplifier for driving an audio output signal to headphones or speakers.
  • a power amplifier amplifies an audio signal by taking energy from a power supply and controlling an audio output signal to match an input signal shape but with a larger amplitude.
  • amplifier architectures e.g., Class A, Class B, and Class AB amplifiers
  • Class A, Class B, and Class AB amplifiers provide for only a single power supply for a power amplifier
  • some architectures provide for at least two supply voltages for powering a power amplifier, in order to achieve greater power efficiency over single or constant power supply voltage architectures.
  • a Class H amplifier may have an infinitely variable voltage supply rail that tracks an envelope of an output signal of the Class H amplifier.
  • the output supply rail may be modulated such that the rail is only slightly larger than a magnitude of the audio output signal at any given time.
  • switched-mode power supplies may be used to create the output signal-tracking voltage rails. Accordingly, a Class H amplifier may increase efficiency by reducing the wasted power at output driving transistors of the amplifier.
  • stereo audio systems may include a left audio channel and a right audio channel.
  • some audio systems may include a low- frequency channel (e.g., for reproducing audio via a "woofer") and a high-frequency channel (e.g., for reproducing audio via a "tweeter").
  • a low- frequency channel e.g., for reproducing audio via a "woofer”
  • a high-frequency channel e.g., for reproducing audio via a "tweeter”
  • it may be advantageous to do so in order to reduce size, cost, and complexity of an audio system.
  • to supply power from a single voltage supply to a plurality of Class H amplifier channels may be challenging, as each of the plurality of channels may have varying supply requirements, a problem not adequately addressed using traditional approaches.
  • one or more disadvantages and problems associated with existing approaches to supplying voltages to a plurality of amplifiers may be reduced or eliminated.
  • a method may include monitoring a respective signal for each of a plurality of amplifiers and, based on the respective signals, and a respective requirement associated with each of the plurality of amplifiers, setting a power supply level of a single signal- variant power supply configured to deliver electrical energy to the plurality of amplifiers such that the respective requirements are satisfied.
  • a control circuit may include at least one input for monitoring a respective signal for each of a plurality of amplifiers, an output for outputting at least one control signal for controlling a power supply level of the single signal-variant power supply configured to deliver electrical energy to the plurality of amplifiers, and decision and control logic.
  • the decision and control logic may be configured to monitor the respective signals for each of the plurality of amplifiers and, based on the respective signals, and a respective requirement associated with each of the plurality of amplifiers, set a power supply level of the single signal- variant power supply and outputting the at least one control signal to control the power supply level such that the respective requirements are satisfied.
  • an apparatus may include a plurality of amplifiers, a single signal-variant power supply configured to deliver electrical energy to the plurality of amplifiers, and a control circuit.
  • the control circuit may be configured to monitor a respective signal for each of the plurality of amplifiers and, based on the respective signals, and a respective requirement associated with each of the plurality of amplifiers, set a power supply level of the single signal-variant power supply such that the respective requirements are satisfied.
  • FIGURE 1 is an illustration of an example personal audio device, in accordance with embodiments of the present disclosure
  • FIGURE 2 is a block diagram of selected components of an example audio integrated circuit of a personal audio device, in accordance with embodiments of the present disclosure
  • FIGURE 3 is a block diagram of selected components of another example audio integrated circuit of a personal audio device, in accordance with embodiments of the present disclosure
  • FIGURE 4 is a block diagram of selected components of yet another example audio integrated circuit of a personal audio device, in accordance with embodiments of the present disclosure.
  • FIGURE 1 is an illustration of an example personal audio device 1, in accordance with embodiments of the present disclosure.
  • FIGURE 1 depicts personal audio device 1 coupled to a headset 3 in the form of a pair of earbud speakers 8 A and 8B.
  • Headset 3 depicted in FIGURE 1 is merely an example, and it is understood that personal audio device 1 may be used in connection with a variety of audio transducers, including without limitation, headphones, earbuds, in-ear earphones, and external speakers.
  • a plug 4 may provide for connection of headset 3 to an electrical terminal of personal audio device 1.
  • Personal audio device 1 may provide a display to a user and receive user input using a touch screen 2, or alternatively, a standard liquid crystal display (LCD) may be combined with various buttons, sliders, and/or dials disposed on the face and/or sides of personal audio device 1.
  • personal audio device 1 may include an audio integrated circuit (IC) 9 for generating an analog audio signal for transmission to headset 3 and/or another audio transducer.
  • IC audio integrated circuit
  • FIGURE 2 is a block diagram of selected components of an example audio system 9A of a personal audio device, in accordance with embodiments of the present disclosure.
  • example audio system 9 A may be used to implement audio system 9 of FIGURE 1.
  • audio system 9 A may include a plurality of amplifiers 16, a control circuit 20, and a signal- variant power supply 28.
  • Each amplifier 16 may be configured to convert a respective digital audio input signal (e.g., DIG_IN A , DIG_IN B , ⁇ .
  • each amplifier 16 may process and amplify a particular channel of audio for playback (e.g., left channel or right channel, low-frequency channel or high- frequency channel).
  • each amplifier 16 may include memory registers 12 configured to buffer such amplifier's respective digital audio input signal DIG_IN. Such buffering may impose a delay in the audio processing path for a particular channel, which may allow time for control (e.g., control of a supply voltage of an amplifier 16) of amplifier 16 prior to the audio signal propagating to the output of amplifier 16 of the channel.
  • control e.g., control of a supply voltage of an amplifier 16
  • Each amplifier 16 may include a digital-to-analog converter (DAC) 14, which may receive the buffered digital audio input signal DIG_IN for the respective channel and convert such buffered digital audio input signal to a respective analog signal VI (e.g., I A, VINB, ⁇ ⁇ ⁇ , Vnsrx, which may be referred to herein generically as "VIN")- DAC 14 may supply analog signal VIN to an output stage amplifier 26 which may amplify or attenuate audio input signal VIN to provide a respective audio output signal VOUT, which may operate a speaker, headphone transducer, a line level signal output, and/or other suitable output.
  • DAC digital-to-analog converter
  • An output stage amplifier 26 may comprise any suitable output stage for driving an analog signal to a transducer, including without limitation a Class D amplifier, a Class AB amplifier, a Class G amplifier, and a Class H amplifier.
  • transducers driven by the various amplifiers 16 may include any suitable transducer, including without limitation an acoustic loudspeaker, a headphone earpiece, a haptic transducer, and an ultrasonic emitter.
  • output stage amplifier 26 of each amplifier 16 may be supplied electrical energy from signal-variant power supply 28.
  • Signal-variant power supply 28 may output a variable supply voltage VSUPPLY based on one or more control signals VOLTAGE CONTROL communicated from control circuit 20, as described in greater detail below.
  • Supply voltage VSUPPLY output by signal-variant power supply 28 may be selected from a plurality of discrete voltages, or may include an infinite number of voltages between a minimum and maximum voltage.
  • Signal-variant power supply 28 may comprise any suitable power supply for supplying electrical energy to a load, including without limitation, a boost converter power supply, a buck converter power supply, a buck-boost converter power supply, and a linear power supply.
  • Control circuit 20 may include at least one input for receiving a respective signal for each of the plurality of amplifiers 16, an output for outputting at least one control signal (e.g., VOLTAGE CONTROL) for controlling the power supply level of single signal-variant power supply 26, and decision and control logic 22.
  • Decision and control logic 22 may be configured to monitor the respective signals received from each of the plurality of amplifiers 16 and, based on the respective signals, and a respective requirement associated with each of the plurality of amplifiers 16, set a power supply level of single signal- variant power supply 26 and output the at least one control signal (e.g., VOLTAGE CONTROL) to control the power supply level such that the respective requirements are satisfied.
  • monitoring the respective signals may comprise monitoring respective signal content of the respective signals, the signal content comprising one or more of a voltage level (e.g., a voltage level of an audio output voltage VOUT to be generated from a digital audio input signal DIG_IN), a current level (e.g., a target current driven into a load based on a digital audio input signal DIG_IN), a mathematical derivative or mathematical integral of the voltage level, a mathematical derivative or mathematical integral of the current level, and in-band spectral content of an audio output voltage VOUT or digital audio input signal DIG_IN.
  • Decision and control logic 22 may receive such information from the respective memory registers 12 of the various amplifiers 16 or may determine such information from data received from the respective memory registers 12 of the various amplifiers 16.
  • Communication from memory registers 12 of the various amplifiers 16 to decision and control logic 22 may be via any suitable digital communication protocol or analog communication protocol.
  • memory registers 12 or other components of amplifiers 16 may also communicate requirements for the amplifiers.
  • Such requirements may include any suitable requirements for an amplifier 16 or an audio output signal generated by such amplifier, including without limitation an acceptable distortion level, an acceptable noise level, a required voltage supply headroom, a frequency range, and/or any other suitable requirement.
  • the requirements may be communicated via the communication protocol using variables representing advisory controls of the plurality of amplifiers 16.
  • decision and control logic 22 may receive from each amplifier 16 a respective signal (e.g., the buffered digital audio input signal DIG_IN or a signal derived therefrom) and a voltage headroom requirement for such amplifier 16. Then, based on the respective signals and the respective requirements, decision and control logic 22 may determine for each amplifier 16 a respective minimum- required power supply level sufficient to satisfy the respective requirement (e.g., the headroom requirement) of such amplifier 16. Such that the headroom requirement is satisfied for each amplifier 16, decision and control logic 22 may set the power supply level of signal-variant power supply 28 to a maximum of the respective minimum- required power supply levels.
  • a respective signal e.g., the buffered digital audio input signal DIG_IN or a signal derived therefrom
  • decision and control logic 22 may determine for each amplifier 16 a respective minimum- required power supply level sufficient to satisfy the respective requirement (e.g., the headroom requirement) of such amplifier 16. Such that the headroom requirement is satisfied for each amplifier 16, decision and control logic 22 may set the power supply level of signal-
  • decision and control logic 22 may set the power supply level of signal-variant power supply 28 based on any suitable analysis of the respective signals received from the various amplifiers 16, including one or more of a frequency analysis of the respective signals, a time domain analysis of the respective signals, a power consumption optimization setting for the plurality of amplifiers, and a target distortion for at least one of the plurality of amplifiers.
  • FIGURE 3 is a block diagram of selected components of an example audio system 9B of a personal audio device, in accordance with embodiments of the present disclosure.
  • example audio system 9B may be used to implement audio system 9 of FIGURE 1.
  • the structure and function of example audio system 9B is in many respects identical to that of example audio system 9A, except that in example audio system 9B, control circuit 20 and signal- variant power supply 28 are internal to an amplifier 16B of the plurality of amplifiers 16.
  • FIGURE 4 is a block diagram of selected components of an example audio system 9C of a personal audio device, in accordance with embodiments of the present disclosure.
  • example audio system 9C may be used to implement audio system 9 of FIGURE 1.
  • the structure and function of example audio system 9C is in many respects identical to that of example audio system 9A, except that in example audio system 9C, each amplifier 16 may be responsible for reproducing the output content of only a single channel of a digital audio input signal DIG_IN delivered over a common digital interface, and decision and control logic 22 may receive and process all channels of digital audio input signal DIG_IN and requirements of the various amplifiers 16 in order to set the supply voltage of signal- variant power supply 28.
  • control circuit 20 and signal-variant power supply 28 are depicted in FIGURE 4 as external to each amplifier 16, in some embodiments, one or more of control circuit 20 and signal - variant power supply 28 may be internal to an amplifier 16.
  • audio systems 9 A, 9B, and 9C may be implemented on a single integrated circuit or on a plurality of coupled integrated circuits.
  • references in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, or component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative.

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Multimedia (AREA)
  • Health & Medical Sciences (AREA)
  • General Health & Medical Sciences (AREA)
  • Otolaryngology (AREA)
  • Physics & Mathematics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Amplifiers (AREA)

Abstract

Des modes de réalisation de la présente invention concernent un circuit de commande qui peut comprendre au moins une entrée destinée à surveiller un signal respectif pour chacun d'une pluralité d'amplificateurs, une sortie destinée à délivrer au moins un signal de commande pour commander un niveau d'alimentation électrique de l'alimentation électrique à variation de signal unique configurée pour délivrer de l'énergie électrique à la pluralité d'amplificateurs, et une logique de décision et de commande. La logique de décision et de commande peut être configurée pour surveiller les signaux respectifs pour chacun de la pluralité d'amplificateurs et, en se basant sur les signaux respectifs et une exigence respective associée à chacun de la pluralité d'amplificateurs, régler un niveau d'alimentation électrique de l'alimentation électrique à variation de signal unique et délivrer en sortie l'au moins un signal de commande afin de commander le niveau d'alimentation électrique de telle sorte que les exigences respectives soient satisfaites.
PCT/US2017/027743 2016-04-20 2017-04-14 Alimentation électrique à variation de signal unique pour une pluralité d'amplificateurs WO2017184458A1 (fr)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US201662325231P 2016-04-20 2016-04-20
US62/325,231 2016-04-20
US15/349,771 2016-11-11
US15/349,771 US20170310280A1 (en) 2016-04-20 2016-11-11 Single signal-variant power supply for a plurality of amplifiers

Publications (1)

Publication Number Publication Date
WO2017184458A1 true WO2017184458A1 (fr) 2017-10-26

Family

ID=60089837

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2017/027743 WO2017184458A1 (fr) 2016-04-20 2017-04-14 Alimentation électrique à variation de signal unique pour une pluralité d'amplificateurs

Country Status (2)

Country Link
US (1) US20170310280A1 (fr)
WO (1) WO2017184458A1 (fr)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11929715B2 (en) 2020-08-07 2024-03-12 Microchip Technology Incorporated Method and apparatus for modulating amplifier supply voltage for reducing power dissipation
CN116389976B (zh) * 2021-08-19 2023-12-01 荣耀终端有限公司 提高外放声音效果的方法及相关装置

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080116979A1 (en) * 2006-06-30 2008-05-22 Lesso John P Amplifier circuit and methods of operation thereof
US20100164630A1 (en) * 2008-12-29 2010-07-01 Texas Instruments Incorporated Adaptive signal-feed-forward circuit and method for reducing amplifier power without signal distortion
US20150008962A1 (en) * 2013-07-05 2015-01-08 Wolfson Microelectronics Plc Signal envelope processing
US20150045095A1 (en) * 2013-08-06 2015-02-12 Aura Semiconductor Pvt. Ltd. Power amplifier providing high efficiency

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6738318B1 (en) * 2001-03-05 2004-05-18 Scott C. Harris Audio reproduction system which adaptively assigns different sound parts to different reproduction parts
JP4356271B2 (ja) * 2001-08-07 2009-11-04 ソニー株式会社 音声信号再生装置
US7375441B2 (en) * 2004-11-09 2008-05-20 Matsushita Electric Industrial Co., Ltd. Systems and methods for dynamically affecting power dissipation in a disk drive including a fixed output voltage regulator
US20090323985A1 (en) * 2008-06-30 2009-12-31 Qualcomm Incorporated System and method of controlling power consumption in response to volume control
US20120275624A1 (en) * 2011-04-28 2012-11-01 Szuyu Ho Energy-saving audio-amplifier control device
US9559642B2 (en) * 2015-01-02 2017-01-31 Logitech Europe, S.A. Audio delivery system having an improved efficiency and extended operation time between recharges or battery replacements
US20170139849A1 (en) * 2015-11-17 2017-05-18 HGST Netherlands B.V. Driverless storage device using serially-attached non-volatile memory

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20080116979A1 (en) * 2006-06-30 2008-05-22 Lesso John P Amplifier circuit and methods of operation thereof
US20100164630A1 (en) * 2008-12-29 2010-07-01 Texas Instruments Incorporated Adaptive signal-feed-forward circuit and method for reducing amplifier power without signal distortion
US20150008962A1 (en) * 2013-07-05 2015-01-08 Wolfson Microelectronics Plc Signal envelope processing
US20150045095A1 (en) * 2013-08-06 2015-02-12 Aura Semiconductor Pvt. Ltd. Power amplifier providing high efficiency

Also Published As

Publication number Publication date
US20170310280A1 (en) 2017-10-26

Similar Documents

Publication Publication Date Title
US10447217B2 (en) Amplifier with configurable final output stage
US9955254B2 (en) Systems and methods for preventing distortion due to supply-based modulation index changes in an audio playback system
US9985587B2 (en) Switched mode converter with variable common mode voltage buffer
US10763811B2 (en) Gain control in a class-D open-loop amplifier
CN110612665B (zh) 具有可配置的最终输出级的放大器的校准
US10236827B2 (en) Offset calibration for amplifier and preceding circuit
US10873811B1 (en) Low-latency audio output with variable group delay
KR102374790B1 (ko) 차지 펌프 잡음을 감소시키기 위한 신호 경로의 잡음 전달 함수의 제어
US10193505B2 (en) Configurable control loop topology for a pulse width modulation amplifier
WO2017184458A1 (fr) Alimentation électrique à variation de signal unique pour une pluralité d'amplificateurs
US10658988B1 (en) Open-loop class-D amplifier system with analog supply ramping
CN110603731B (zh) 具有可配置最终输出级的放大器中的切换
GB2549571A (en) Single signal-variant power supply for a pluarity of amplifiers
WO2022256180A1 (fr) Minimisation de la distorsion harmonique totale et de la distorsion d'intermodulation induite par l'alimentation électrique dans un amplificateur à modulation d'impulsions en largeur de classe d asymétrique
US10644661B2 (en) Variable output resistance in a playback path with open-loop pulse-width modulation driver
US10594310B2 (en) Full-scale range enhancement in a dual-path pulse width modulation playback system
US10833657B2 (en) Variable output resistance in a playback path with closed-loop pulse-width modulation driver
KR102216831B1 (ko) 이중-경로 펄스 폭 변조 시스템의 교정
US11190148B2 (en) Minimizing idle channel noise in a class-D pulse width modulation amplifier
US11438697B2 (en) Low-latency audio output with variable group delay
US11798978B2 (en) On-chip inductor with audio headphone amplifier

Legal Events

Date Code Title Description
NENP Non-entry into the national phase

Ref country code: DE

121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17733107

Country of ref document: EP

Kind code of ref document: A1

122 Ep: pct application non-entry in european phase

Ref document number: 17733107

Country of ref document: EP

Kind code of ref document: A1